Many vehicle seat belt retractors include a vehicle sensitive sensor. The vehicle sensitive sensor is responsive to certain vehicle conditions, such as vehicle deceleration and tilt, for preventing rotation of a spool of the retractor in a belt withdrawal direction.
It is common in some vehicles to locate the seat belt retractor in the backrest portion of the seat. When a seat belt retractor that is mounted in the backrest portion of the seat includes a vehicle sensitive sensor, the reclining or folding of the backrest portion of the seat may result in the vehicle sensitive sensor preventing rotation of the spool in a belt withdrawal direction. The spool of the retractor, however, may still rotate in the belt retraction direction to retract seat belt webbing. If the seat belt webbing retracts into the retractor when the backrest portion of the seat is in a folded or reclined condition and the vehicle sensitive sensor prevents rotation of the spool in the belt withdrawal direction, the seat belt webbing is prevented from being withdrawn from the retractor, which may prevent the backrest portion of the seat from being returned to an upright position.
Similarly, prior to or during installation into a vehicle, the vehicle sensitive sensor of a retractor may be actuated to prevent rotation of the spool in the belt withdrawal direction. If, while the vehicle sensitive sensor is in the actuated condition, enough seat belt webbing is retracted into the retractor to pack the spool of the retractor solidly, the vehicle sensitive sensor may be prevented from returning to an unactuated condition. The seat belt webbing may thus be prevented from being withdrawn from the retractor.
A mechanism for disabling the vehicle sensitive sensor under certain conditions is desired. Such a mechanism, however, should not hinder the proper operation of the vehicle sensitive sensor when the seat belt webbing is being used for restraining an occupant in a vehicle seat.